Republican presidential hopefuls (l. to r.) former Sen. Rick Santorum (R) of Pennsylvania, Rep. Michele Bachmann (R) of Minnesota, former Speaker of the House Newt Gingrich (R) of Georgia, former Massachusetts Gov. Mitt Romney, Rep. Ron Paul (R) of Texas, former Minnesota Gov. Tim Pawlenty, and former Godfather's Pizza CEO Herman Cain took part in the first New Hampshire debate of the 2012 campaign at St. Anslem College in Manchester, N.H., on June 13.

Washington — Rep. Michele Bachmann stole the spotlight Monday night in New Hampshire, using the second GOP presidential debate of the season to announce that she is indeed running for president.

The Minnesota congresswoman and leader of the House Tea Party Caucus had telegraphed a campaign for weeks, but she made it official in her opening statement – triggering the early headline of the evening. Ms. Bachmann then delivered a strong debate performance, articulating her conservative views, demonstrating her status as an activist member of the House, and introducing herself to voters.

The most eye-popping point on Bachmann’s résumé: She and her husband have been foster parents to 23 children, in addition to raising five children of their own. She pointed this out twice Monday night.

The second winner of the evening was Mitt Romney, the former governor of Massachusetts. The early front-runner for the Republican nomination could have faced “incoming” from other contenders, particularly over his Massachusetts health-care reform – a model for President Obama’s reform – and his changed views on abortion. But the six other candidates on stage took a pass.

Instead, former President Reagan’s 11th Commandment – “Thou shalt not speak ill of any fellow Republican” – got a good workout. And Mr. Romney was allowed to look calmly in command and to repeat his explanation for why “Romneycare” was a legitimate initiative at the state level but not an appropriate model for the entire country.

“Ours was a state plan, a state solution, and if people don't like it in our state, they can change it,” Romney said. “That's the nature of why states are the right place for this type of responsibility. And that's why I introduced a plan to repeal Obamacare and replace it with a state-centric program.”

One big question of the evening was whether former Minnesota Gov. Tim Pawlenty would go after Romney on health care. On “Fox News Sunday” the day before, he had coined the term “Obamneycare,” a ready-made sound bite to fling again at the front-runner, this time to his face. But Mr. Pawlenty backed away, despite the efforts of moderator John King of CNN to spark a fight. “Minnesota nice” prevailed again, as it had in the first debate on May 5.

The early line from pundits was that Pawlenty missed a golden opportunity to go after Romney and begin to build a profile as a fighter. After all, many asked, if he is not willing to take on the front-runner, how would he behave toward Mr. Obama in the general election?

An alternate view is that Pawlenty remains largely unknown to most voters, and that he chose to take the biggest opportunity to date to introduce himself to the public in a positive light. There are at least seven months to go before the first nominating contests, and Pawlenty still has time. The bad news for the Minnesotan is that he didn’t distinguish himself in other ways during the two-hour event. Romney even beat him in dropping a reference to the Boston Bruins – noting they were up 4-0 in Game Six of the Stanley Cup finals, winning a big cheer from the New Hampshire crowd.

Another loser of the evening was businessman Herman Cain. He won big during the first debate, speaking bluntly and plainly as the only nonpolitician in the field, and he has seen his poll numbers rise steadily since then. But Mr. Cain, former CEO of Godfather’s Pizza, got tangled up in his explanation of a previous statement of why he would not be “comfortable” having a Muslim in his administration.

“I would not be comfortable because you have peaceful Muslims and then you have militant Muslims, those that are trying to kill us,” Cain said. “And so, when I said I wouldn't be comfortable, I was thinking about the ones that are trying to kill us.”

When pressed by Mr. King on whether he would have a “loyalty test” for a Muslim seeking to serve in a Cain administration, he said: “I would ask certain questions, John. And it's not a litmus test. It is simply trying to make sure that we have people committed to the Constitution first in order for them to work effectively in the administration.”

Romney was handed the followup, and steered clear of the “loyalty test” issue. “I think we recognize that the people of all faiths are welcome in this country,” he said. “Our nation was founded on a principle of religious tolerance. That's in fact why some of the early patriots came to this country and we treat people with respect regardless of their religious persuasion.”

Romney did not mention his own faith – Mormonism – but his answer reflected his view that his religious beliefs should not be a factor as voters judge his fitness for the presidency. Some voters, especially evangelicals, say they’re not comfortable with the idea of a Mormon president, an issue that could hurt Romney in the primaries.

Another question heading into the New Hampshire debate was how former House Speaker Newt Gingrich would perform. Most of his senior staff resigned last week over his unorthodox strategy, which is light on in-person campaigning and heavy on social media and debates.

Mr. Gingrich probably did himself no favors. When asked about his recent assertion that the GOP plan for Medicare, authored by House Budget Committee Chairman Paul Ryan, was “right-wing social engineering” – a comment he later backed away from – he offered this:

“If you're dealing with something as big as Medicare and you can't have a conversation with the country where the country thinks what you're doing is the right thing, you better slow down,” Gingrich said. “Remember, we all got mad at Obama because he ran over us when we said don't do it. Well, the Republicans ought to follow the same ground rule. If you can't convince the American people it's a good idea, maybe it's not a good idea.”

The Ryan plan would turn Medicare into a voucher system, ending it as a fee-for-service entitlement. Public opinion on the idea is negative, and Democrats have used it as a blunt instrument to attack Republicans. But Gingrich’s critique has injected a discordant note within the GOP, and his continuing defense of it Monday night reignited that issue.

In the end, though, the night belonged to Bachmann and Romney. As a sitting member of Congress, Bachmann could speak in the present tense about her actions to fight the Obama agenda.

“I was the very first member of Congress to introduce the full-scale repeal of Obamacare,” she said.

It’s way too soon to say whether the GOP nomination race will boil down to Bachmann versus Romney. But there’s certainly a path to that outcome. Bachmann, who is originally from Iowa, could be a strong contender in the Iowa caucuses, where social conservatives often win the day. Caucus-goers could hesitate over the fact that she’s only a member of the House – not a typical launch pad for winning the presidency.

Bachmann has many miles to go as a full-fledged candidate for voters to determine her viability. But she speaks the tea party and social conservative language fluently, and thus she’s a force to watch.

See also the Monitor's Election 101 series of profiles of these Republican candidates for president: